CT Cervical Spine — Unenhanced, Thin Section
Skull base through the top of T1 at minimum; the cervicothoracic junction must be visualised or the study is incomplete.
Timings, volumes and delays here are representative values drawn from published guidance. Scanner generation, injector, cardiac output and local preference all move them. Confirm against your department's own protocol before you rely on a number.
When to use it
- Blunt cervical spine trauma in a patient not cleared by a validated clinical decision rule.
- Any obtunded or intubated trauma patient in whom clinical clearance is impossible.
- Known or suspected ankylosing spinal disorder after even minor trauma, where fracture risk is high and radiographs are unreliable.
- Suspected bony destruction from infection or malignancy where MRI is unavailable or contraindicated.
- Post-operative assessment of instrumentation and fusion.
Technique
- Sagittal and coronal reformats at thin slice thickness are required for the study to meet published standards; axial-only review misses horizontally oriented fractures.
- Occipital condyle and C1-C2 detail needs dedicated review, often on angled reformats.
- Prevertebral soft tissues are assessed on the soft-tissue series, not the bone series.
Where it goes wrong
- A study that stops above T1 leaves the commonest site of missed injury unassessed.
- Beam-hardening across the shoulders degrades C6-T1 in the broad-shouldered patient; increasing dose over that segment is more effective than repeating the whole scan.
- CT is a bone study — a normal CT does not exclude ligamentous injury or cord contusion, which is the standard reason to proceed to MRI.
- Motion between the acquisition and the reformats is not a thing; motion during it destroys both. Re-scanning after settling beats reformatting bad data.
Clinical questions that reach this study
Contrast
Acquisition
- Breathing
- Suspended respiration where possible; shoulders relaxed and drawn caudally if spinal precautions allow.
- Reconstruction
- Thin-section acquisition reconstructed in bone and soft-tissue algorithms with sagittal and coronal reformats, which are explicitly part of the standard rather than an optional extra.
- Preparation
- Collar and immobilisation stay on unless the referring team has cleared removal. Shoulders drawn down where safe, to reduce beam-hardening across C6-T1 — never at the cost of spinal precautions.
Phases
Each phase is authored once and shared across every protocol that uses it, so the physiology below is the same wherever you meet it.
- Non-contrast (unenhanced)No injection. Acquired before any contrast is given.
Shows intrinsic tissue attenuation, and nothing else. The transferable principle is that contrast is anti-signal for anything that is already dense: calcification, acute haemorrhage, urinary and biliary calculi, iodine-containing or haemorrhagic fluid, and intrinsic fat all lose conspicuity, or become uninterpretable, once surrounding tissue enhances. It is also the only baseline against which enhancement can be measured, so any protocol that quantifies enhancement or washout (a lesion "enhances by X HU", adrenal absolute washout, renal mass characterisation) is arithmetically impossible without it. Conversely, an unenhanced series adds dose and no information whenever the question is purely about vascularity or perfusion.
Safety checks this protocol carries
Derived from the contrast agent and phases above, not authored here — which is why they cannot drift apart from what the protocol actually does.
- Child-sized technique and contrast dose· radiographer at scan